I even remember black hats and t-shirts bearing the repetitive numerical sequence in white. It was the first time I (and lots of other people) noticed that some folks are apparently fascinated with unusual dates.

There are basically three types of “special dates” that when shown in their numerical form become something of interest (to some people). There’s the repetitive kind – like Jan. 1, 2001, which began it all with 01-01-01 – and the sequential kind – like 01-02-03, which occurred on Jan. 2, 2003. Then there are “Palindrome dates” which are the same forward or backward, whether abbreviated or by full year (like Sept. 9, 1929, which is that same either way you slice or dice it, whether 9-29-29 or 9-29-1929).

Doug Davison

Now, I’ve always been pretty weak with numbers and math, but I can comprehend that the nature of the world-standard Gregorian calendar – and its 12-month, 365-day years – means that repetitive and sequential special dates only happen during the first 14 years of a given century. But as far as Palindrome dates go, that concept makes my mind spin and I’ll leave it to the experts to indicate their frequency.

But mathematical riddles and dates aside, the fundamental structure of repetitive and sequential dates means that when 11-12-13 came and went earlier this month, that left only one more to go before a moratorium of about 87 years begins until another comes along. Yep, when 12-13-14 takes place in mid-December of next year, it will be the 12th and final sequential date of the century and will wrap up the repetitive and sequential date fun until another 01-01-01 pops up in 2101 (for the record, Dec. 12, 2012 – a.k.a. 12-12-12 – was this century’s last repetitive date).

Oh, no, whatever will we do.

I honestly don’t relate to the excitement surrounding “special” dates, but in some instances they can and do cause quite a commotion. I guess 11-11-11 was such a big deal in China that lots of Chinese couples arranged to be married on that repetitive date (not that’s it’s really relevant, but while some of those couples might try to move into a home with an address of 1111 11th Street in a city where the area code is 111 and the zip code is 11111, I’m guessing not too many will have 11 kids).

The same applies to some extent here in the States, too, as a leading bridal wear company estimated that more than eight times more weddings took place on 11-12-13 than on 11-12-12.

Not surprisingly in this world of easy access to mass information, there’s plenty out there to interest fans of repetitive and sequential dates – even a web site that lists significant events or moments that took place on each of this century’s repetitive dates. And for those who want to take the matter a step further, there’s even “sequential time,” like the moment that occurred one hour, two minutes and three seconds after midnight on April 5, 2006 that can numerically be documented as 1:02:03 4-5-06 (that’s so cute that I’ll bet more than one person bought a lottery ticket bearing those numbers that day).

Anyway, here we are on the cusp of a lengthy stretch of years when there won’t be any special dates to embroider on hats or create websites over. Wow, think about it: 12-13-14 is only 300 and some-odd days away, and there won’t be a similar date for dang near a century.

I guess now’s the time to start planning for the big day. Or not.

Doug Davison is a writer, photographer and newsroom assistant for the Houston Herald. Email: ddavison@houstonherald.com.